Methods of manufacturing asphalt with lime pellets

Abstract

Lime pellets can be used in preparing asphalt compositions. The pellets are characterized as having a substantially rigid structure with a dimension greater than about 1.5 mm and being compatible with a hot mix asphalt so as to dissolve in liquid asphalt. The pellets condition an end product of asphalt pavement by being dissolved into a hot mix asphalt composition during the manufacture of such an asphalt. The method of conditioning includes providing the lime pellets, and mixing the lime pellets with a hot mix asphalt ingredient, wherein the ingredient is at least one of an aggregate or asphalt cement. The asphalt and lime pellets are heated to a temperature sufficient for the lime pellets to be dissolved.

1. A method of manufacturing asphalt for use in asphalt pavement, the method comprising;
 introducing a plurality of lime pellets into a liquid asphalt cement, said lime pellets being comprised of lime fines held together with a binder, wherein at least a portion of the lime pellets are characterized as having a dimension greater than about 1.5 mm; and 
 dissolving the plurality of lime pellets in the liquid asphalt cement, wherein each lime pellet substantially dissolves within 30 seconds of being introduced into the liquid asphalt cement when heated to a temperature greater than about 150° C. 
 
     
     
       2. A method as in  claim 1 , wherein the plurality of lime pellets provide lime at greater than about 10% by weight of total asphalt cement. 
     
     
       3. A method as in  claim 1 , further comprising adding an aggregate to the liquid asphalt cement, wherein the amount of aggregate results in the lime being present in an amount of about 0.05% to about 5% by weight of the aggregate. 
     
     
       4. A method as in  claim 1 , wherein each lime pellet comprises:
 lime fines at greater than about 1% by total weight of the pellet; and 
 an asphalt-compatible binder mixed with the lime fines in an amount and disposition sufficient to form a pellet. 
 
     
     
       5. A method as in  claim 4 , wherein the binder is characterized by less than about 50% by weight of total binder being sulfur. 
     
     
       6. A method as in  claim 4 , wherein at least a portion of the lime pellets are characterized as having lime fines at a concentration greater than about 31% by total weight of the lime pellet. 
     
     
       7. A method as in  claim 4 , wherein the asphalt-compatible binder is present at about 0.5% to about 69% by total weight of the pellet. 
     
     
       8. A method as in  claim 7 , wherein the asphalt-compatible binder is comprised of a hydrophobic binder. 
     
     
       9. A method as in  claim 7 , wherein the asphalt-compatible binder is comprised of a hydrophilic binder. 
     
     
       10. A method as in  claim 7 , wherein the binder is comprised of at least one of bitumens, tall oil pitch, asphalt cements, lignosulphonates, latexes, rubbers, polysaccharide or derivative thereof, tannin liquor, collagen derivative, beet molasses derivative, plastomer polymers, elastomer polymers, aliphatic petroleum distillate, styrene-butadiene-styrenes, styrene-ethylene/butylene-styrenes, styrene isoprenes, styrene ethylbutylenes, styrene butadiene rubber latexes, polychloroprene latexes, polyisoprenes, polyethylene acetates, polyethylenes and derivatives, polypropylenes and derivatives, acrylic polymers, silicone-based polymers, and polydimethylsiloxanes. 
     
     
       11. A method as in  claim 7 , wherein the lime pellet is comprised of at least one of manganese oxide, salt, rheology-modifier, sand, silica, fly ash, ceramic particles, glass particles, pozzolanic materials, filler materials, solvent, aggregate, color-imparting agent, or coating. 
     
     
       12. A method as in  claim 4 , wherein the lime fines are comprised of calcium hydroxide in an amount greater than 31% by weight. 
     
     
       13. A method as in  claim 4 , wherein the lime fines are comprised of calcium oxide in an amount greater than 31% by weight. 
     
     
       14. A method as in  claim 4 , wherein at least a portion of the lime pellets are further comprised of a minor amount of limestone. 
     
     
       15. A method as in  claim 4 , wherein at least a portion of the lime pellets are substantially devoid of limestone. 
     
     
       16. A method of manufacturing hot mix asphalt for use in asphalt pavement, the method comprising:
 introducing a plurality of lime pellets into a heated liquid asphalt cement, said lime pellets being comprised of lime fines held together with a binder, wherein each lime pellet comprises:
 lime fines at greater than about 1% by total weight of the pellet; and 
 an asphalt-compatible binder mixed with the lime fines in an amount and disposition sufficient to form a pellet, wherein the lime pellets are characterized as having a dimension greater than about 1.5 mm; and 
 
 mixing the lime pellets with the heated liquid asphalt cement, wherein the lime pellet provides lime at greater than about 10% by weight of the asphalt cement. 
 
     
     
       17. A method as in  claim 16 , further comprising introducing an aggregate into the heated liquid asphalt and mixing the composition. 
     
     
       18. A method as in  claim 16 , further comprising:
 combining the plurality of lime pellets with an aggregate so that the lime pellet provides lime from about 0.05% to about 5% by weight of the aggregate; and 
 introducing aggregate into the heated liquid asphalt with the lime pellets. 
 
     
     
       19. A method as in  claim 16 , further comprising at least one of the following:
 removing the plurality of lime pellets from storage; 
 combining the lime pellets with a hot mix asphalt ingredient, the ingredient being at least one of an aggregate or asphalt cement; or 
 dissolving the lime pellet in liquid asphalt cement, wherein the asphalt cement is liquefied by being heated to a temperature greater than about 150° C. 
 
     
     
       20. A method as in  claim 16 , wherein at least a portion of the lime pellets are characterized as having lime fines at a concentration greater than about 31% by total weight of the lime pellet. 
     
     
       21. A method as in  claim 16 , wherein the asphalt-compatible binder is present at about 0.5% to about 69% by total weight of the pellet. 
     
     
       22. A method as in  claim 21 , wherein the binder is comprised of at least one of bitumens, tall oil pitch, asphalt cements, lignosulphonates, latexes, rubbers, polysaccharide or derivative thereof, tannin liquor, collagen derivative, beet molasses derivative, plastomer polymers, elastomer polymers, aliphatic petroleum distillate, styrene-butadiene-styrenes, styrene-etheylene/butylene-styrenes, styrene isoprenes, styrene ethylbutylenes, styrene butadiene rubber latexes, polychloroprene latexes, polyisoprenes, polyethylene acetates, polyethylenes and derivatives, polypropylenes and derivatives, acrylic polymers, silicone-based polymers, and polydimethylsiloxanes. 
     
     
       23. A method as in  claim 22 , wherein the lime pellet is comprised of at least one of manganese oxide, salt, rheology-modifier, sand, silica, fly ash, ceramic particles, glass particles, pozzolanic materials, filler materials, solvent, aggregate, color-imparting agent, or coating. 
     
     
       24. A method as in  claim 16 , wherein the lime fines are comprised of calcium hydroxide in an amount greater than 31% by weight. 
     
     
       25. A method as in  claim 16 , wherein the lime fines are comprised of calcium oxide in an amount greater than 31% by weight.